Many electro-optical semi-conductor inspection systems contain at least two detectors.
One way of arranging these detectors is where every detector views a respective part of the inspected article. For example, U.S. Pat. No. 6,693,664 includes a discussion of an arrangement where there are multiple 2-dimensional detectors which are located at the focal plane of the system's imager to creating a continuous imaging surface. U.S. Pat. No. 7,274,444 includes discussion of an embodiment where the multiple 2-dimensional detectors are located with intervals between them.
An arrangement of line or TDI detectors may also be used, with special optics used so that the line detectors view areas that are side by side (see U.S. Pat. No. 6,366,315).
Another way to inspect articles is to let multiple detectors view the same location in the article, but with different imaging modes. U.S. Pat. No. 7,265,900, for example, discusses an embodiment in which all the detectors view the same area in a wafer but with different collection angles.